CHAP. III.
_Of things that equally appertain to Publick and Private Buildings._
ARTICLE I.
_Of_ Aqueducts.
[Sidenote: _Lib. 8. Chap. 6._]
In Order to the bringing of Waters to Towns and Cities, the Level must be exactly taken; to the end, it may be known whether the Waters can be brought thither or no. The Ancients to this end made use of an Instrument called _Corobates_, which was directed by a Lead, and by Water, when the Wind hindered them from making use of the Lead.
They brought their Water three several ways; _viz._ by _Aqueducts_, by Pipes of Lead, and Pipes baked in a _Potter"s_ Furnace. They allowed for the _Channels_ or _Sewers_ of the _Aqueducts_, for every 100 Foot, half a Foot of Declination or Sloping; and if any Hills were in their way, they dug through them, making Vents to give Air at convenient Distances.
The Pipes of Lead were at least 9 Foot long; they made them of bended Sheets or Plates, and of different thicknesses, according to the Proportion of the greatness of the Pipes; these Pipes had likewise their necessary Declination or Sloping, and if any Valley was in the way, they made it equal to the Level with a Wall; they likewise made many Vents, to give the Water Air, and to know where to mend the Pipes.
The Pipes of _Potter"s-Work_, were two Inches thick; they were joyned together with Mortar mixed with Oil, and when they had _Conde_ or _Joynt_ to make, they made use of a red Free Stone which they pierced through, to receive the two Ends of the Pipes.
ART. II.
_Of Wells and Cisterns._
It being remarkt oftentimes that the Water which is under the Earth hath many bad Qualities, and exhales vapours, which often stifles those which work in the _Wells_, after that they are dug, & the Water begins to gather together. The Ancients had this Precaution, to let a Lamp gently down into it, and if it extinguished it, they took it for an Infallible sign that the Water was bad.
The _Cisterns_ were made to receive Rain Water in great Conservatories under Ground, whose Walls on all Sides, and at the bottom were built with Mortar of strong Lime, and Sand, and Pebbles, all well beaten together. They made several Conservatories, and the Water pa.s.sed from one to another, to the end it might leave all the Dirt in the first and second; They likewise put Salt in their _Cistern-Water_ to make it more subtile.
ART. III.
_Of_ Machines _for carrying and lifting up great Stones and Burthens._
[Sidenote: _Lib. 10. Chap. 6._]
_Ctesiphon_ and his Son _Metagenes_, Architects of the Temple of _Ephesus_, invented _Machines_ to carry _great Stones_, out of which _Pillars_ and _Architraves_ were to be made. That which was made to draw the _Pillars_, was but a sort of a Frame as long as the _Pillars_, in the end of which were fastned Pins of Iron, which entred into the ends of the Frame, and served instead of an Axle-tree, the _Pillar_ it self serving for a Wheel: And this had the desired Effect, because of the disposition of the place through which these _Stones_ were to be drawn, which was a flat and level Country.
The other _Machine_ for drawing of _Architraves_, was the same Frame which had two Wheels at each end, which supported the _Architrave_; which served instead of an Axle-tree.
[Sidenote: _Lib. 10. Chap. 2._]
For the raising of great Weights, they had three sorts of _Machines_.
The first was composed of three pieces of Wood, which were joyned together at top by a Pin which went through them all; so that there were two of these pieces which were on one side, a little distance one from the other, and the third was opposite to them; The two which were together on the one side, had a Hand-Mill which drew a Rope, which pa.s.sed within a Truckle with three Pullies, of which that part which had the two Pullies was fastned to the top of the _Machine_, and that which had but one, was fastned to the Weight to be drawn up.
[Sidenote: _Lib. 10. Chap. 2._]
The second _Machine_ was stronger than the first, because the _Moulin_ had more Pullies, and instead of a _Moulin_ or Hand-Mill, it had a great Wheel, whose Axle-tree drew a Rope which pa.s.sed through these Pullies, and upon the Wheel there was another Rope twisted, which was drawn by a Wind-gla.s.s; sometimes the great Wheel was hollow, so that Men could walk within it, and so turn it.
The third had but one long and strong piece of Wood, which was kept up and stayed by Shrowds, as the Mast of a Ship is. By the help of these Shrowds, they bended and turned this piece of Wood where they pleased, drawing the Shrowds fast on the one side, and loosening them on the other. The _Moufl"s_ Crane as well those which were fastned to this piece of Wood, as those which were fastned to the VVeight which was to be drawn up, had each of them three ranks of Pullies, which had three in every rank, that three Ropes might go through them, which were not drawn by Hand-Mills, nor by VVheels, but by Men who pulled several at one time at the same Rope: And that this might be done with the more ease, the three Ropes or Cables after having pa.s.sed the last Pullies of that part of the _Moufle_ which was at the top of the _Machine_; they descended down below, each upon one Pully, which vvas but the height of the Men: this _Machine_ quickly povverfully lifted up the greatest VVeights.
ART. IV.
_Of_ Machines _for Elevating of Waters._
These _Machines_ were of four sorts.
[Sidenote: _Lib. 10._]
The first was the _Tympan_, of which there were two sorts; The first elevated a great deal of Water, but not very high, for it only mounted to the Axle-tree of the _Tympan_, which was a great Wheel made of Planks which made two bottoms divided into eight from the Center to the Circ.u.mference, each Separation, having an opening half a Foot wide near the Circ.u.mference to draw the Water, which being elevated upon the Axle-tree, ran through the Cavities which were hollowed in each Separation.
The Second _Machine_, was a Wheel which elevated the Water as high as its Circ.u.mference, by the help of several Boxes which were fastned round about, and which poured out the Water into a Reeve as the Wheel, having mounted, began to descend.
[Sidenote: _Lib. 10. Chap. 2._]
The Third _Machine_ was a Chain with Buckets, as the one mounted, the other descended, being drawn by the Axle-tree.
The Fourth _Machine_ was the Vice or _Skrew_, which is attributed to _Archimedes_, though _Vitruvius_ makes no mention of the Inventor. This Vice was made of a piece of VVood, long sixteen times its Diameter: about this piece of Wood was put Obliquely a Hoop of Willow VVood besmeared with Pitch, and it was Conducted by turning from one end of the piece of the Wood to the other: Upon this Hoop others were put so that they were like the Vaulting of a Stair-Case whose ascent goes turning. This being done, this Vice was fastned and strengthned with Planks, which were pitched within, and covered with Iron Rings and Plates without: At the two ends of the piece of Wood, were Pins, which entring into the Suckets, made the _Machine_ capable of Motion. This Vice or Skrew was placed according to the bent or sloping of the Triangle Rectangle of _Pythagoras_. This _Machine_ elevated easily a great quant.i.ty of Water, but it could not carry it high.
[Sidenote: _Lib. 10. Chap. 2._]
The Fifth _Machine_, was the Pump of _Ctesibius_; it was composed of two Bodies of Pumps, in which the Suckets having drawn the VVater when they were pulled up, they both pressed it violently into a Pipe which was fastned at the bottom of the Body of the Pump when they went down. For the VVater by the Impulsion of the Sucket, was forced to enter into these Pipes, because it could not go out by the Openings by which it entred, because of the Suckets which stopped them, these two Pipes were joyned together in a _Tambour_, which had likewise its Suckets, which hindred the VVater from descending into the Bodies of the Pumps, after it had been pressed into the _Tambour_, or _Vase_, which had another Pipe, through which the VVater was forced as high as they pleased, by Impulsion of the Suckets.
[Sidenote: _Lib. 10. Chap. 10._]
All these _Machines_ were either _moved_ by Strength of Men, or by VVater-Mills, according to the convenience of the place.
ART. V.
_Of Water-Mills for Grinding of Corn._
[Sidenote: _Lib. 10. Chap. 10._]
_Water-Mills_ were moved by the help of a great VVheel which had many VVings, which were forced by the Current. The Axle-tree of this great VVheel, traversed another VVheel which had Cogs, which made the _Lanterne_ or _Trundle-head_ go, which was placed Horizontally, which was traversed by a Beam of Iron, which entred through above, into an Iron in form of a VVedge, which helped to fasten the Beam in the Mill-stone, above which was the Mill-Hopper, in form of a Funnel.
ART. VI.
_Of other Hydraulick Machines._
There were many other _Machines_ which moved by the help of the VVater, as _Hour-Gla.s.ses_, _Organs_, _Machines_ for Measuring the VVays, and knowing the swiftness or slowness of Sailing.
The _Hour-Gla.s.ses_ marked the Hours by the help of VVater, which pa.s.sing slowly, a little hole made at the bottom of a Vessel, and falling into another, in elevating it self insensibly in the Vessel which it filled, raised a piece of Cork, which hanging at one of the ends of a Chain wrapped about an Axle-tree, and which had at the other end a little Bag full of Sand, and a little lighter than the Cork: for this Chain turning, the Axle-tree likewise turned a Pin or Hand, which marked the Hours upon a Dial.
[Sidenote: _Lib. 10. Chap. 12._]